This invention relates generally to a connector assembly for connecting the contact ends of two conductors, and, more particularly, to a connector assembly having an automatic seal enclosing at least one of the contacts to prevent its exposure to dirt, moisture and other contaminants.
Connector assemblies that join the ends of electrical and fiber optic conductors are well known. A connector assembly typically incorporates two matable housing portions, each of which holds one contact end of the conductor to be joined. Thus, the contacts are connected when the two housings are joined. In situations where a device, such as an avionics module for an aircraft, has numerous output contacts, one portion of a connector assembly can be permanently mounted about each output contact projecting from that device. Thus, when the avionics module is installed in the aircraft, the other portion of each connector assembly is mated to the corresponding connector portion on the device.
Any device, including the avionics module described above, can encounter contaminants such as dirt, dust and moisture while the device is in use or while it is in storage prior to use. Because the contacts on such devices can be highly susceptible to such contaminants, it is desirable to protect the contacts, by sealing them inside of their respective connector assembly housings. In this regard, it should be appreciated that very small contaminant amounts can disrupt a connection between the contact ends of two optical fibers. Thus, an important function of a housing of a connector assembly is to protect its associated contact(s) from contaminants during the time the device is in storage (i.e., when the connector assembly portions are not connected), as well as during the time the device is in use (i.e., when the connector assembly portions are mated together).
Some connector assemblies incorporate plugs or caps that snap on or thread over the mating ends of each of the unmated connector housings, to provide a seal protecting the contact therein from contaminants. While such plugs or caps are generally effective in preventing contamination when the housings of the connector assembly are not joined, they are somewhat labor intensive to install and remove, resulting in higher labor expenses and increased installation times. In addition, the plugs and caps can easily be lost, resulting in yet further inefficiency and the possibility that field personnel will neglect to replace lost plugs and caps, resulting in a failure to protect the contacts of a particular device.
Newer connector assemblies, incorporating elastomeric seals, have been developed to address the shortcomings described above. However, while these connector assemblies are generally effective in protecting contacts from contamination during the times when the connector portions are not interconnected, they also have certain drawbacks. In particular, one of these newer connector assemblies has a female connector housing having an elastomeric membrane with a small cut therein. The male housing is configured to deform the membrane to widen the cut and allow an optical fiber contact to pass therethrough when the male and female housings are joined. In the unconnected position, the small cut is not deformed and can protect the contact inside the female portion from contaminants.
Several disadvantages are associated with the above connector assembly. In particular, because the elastomeric memory of the membrane can fade, the small cut may over time fail to seal after the male housing is removed. Further, should a repair become necessary, the pieces of this connector assembly can be difficult to remove and replace. Another drawback also is associated with the memory of the elastomeric material, the characteristics of which can limit the size of the cut and thus the size of the connector assembly and the contact therein. Yet another drawback of this connector is that the seal provided by the closed cut lacks integrity because the cut in the elastomeric material is not preloaded or biased toward the closed (sealed) position. Because of this lack of preload to hold the small cut closed, changes in temperature and pressure can cause the cut to open, thereby degrading the seal and allowing contaminants to enter the female housing and foul the contact mounted therein.
Another connector assembly incorporates an elastomeric sleeve integrally molded into a female housing. The sleeve extends through a slit in a surrounding elastomeric grommet, which is, in turn, surrounded by a tensioned elastomeric constricting ring. The constricting ring squeezes the grommet and the sleeve into a flattened closed position to seal that portion of the connector assembly. While this connector assembly is generally effective, its component pieces are difficult to remove and replace. Further, because the sleeve is forced open by direct engagement with a male connector housing, the sleeve can be worn or damaged from such contact. Finally, because the circular constricting ring surrounds each contact, a connector assembly with many separate contacts would have a one seal assembly (i.e., a sleeve, a grommet and a constricting ring) mounted about each contact. This arrangement that has one seal assembly for each contact is complicated and thus expensive to manufacture and difficult to repair.
It should therefore be appreciated that there is a need for a connector assembly that has a seal assembly comprised of simple, reliable, easily replaceable, and inexpensive components. The present invention fulfills this need.